Since food is only available seasonally or intermittently at high latitudes, many arctic birds and mammals, including polar bears, Svalbard reindeer, arctic foxes, seals and walruses, naturally accumulate large stores of fat. The quantity of energy stored and the metabolic control of its use are finely adjusted to the habits and habitat of the species. This section is concerned with the cellular structure and anatomical organization of adipose tissue in such naturally obese species. Most labo

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Phosphorus is recognised as a potential poison for automotive catalysts. The phosphorus level in fuel is generally very low (2×10−5 g l−1), but it is present in higher concentrations in engine oils (1.2 g l−1). Phosphorus derived from the engine oil is believed to react with the alumina support, and also to reduce the activity of the noble metal component. This deactivation is particularly important for Pd, with which phosphorus may form an all

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Ensuring good quality air is essential for the protection of public health. Governments worldwide have adopted a range of increasingly demanding measures to curb air pollution with a particular focus on the emissions from motor vehicles. An important part of this strategy has been the development of the three-way catalytic converter to remove exhaust pollutants such as carbon monoxide, unburnt hydrocarbons and nitrogen oxides. This unit takes an in-depth look at the construction of this conve

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The examples in the previous section followed the traditional medical approach, namely that there is a disease, it can be diagnosed (identified), and the cause of the disease, be it viruses, bacteria, pathogens, genes or poisons, can be sought. This section moves away from the medical arena and into the psychological arena, where the symptoms are behavioural. In this case, the symptoms are socially unacceptable behaviour and to the list of causes just mentioned is added family circumstances a

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This section has sought to illustrate the formation of connections between neurons and their targets by exploring a few examples. The picture that emerges is one of cells at different stages of development subjected to a vast array of signals. These signals are the medium through which environmental factors exert their effects. To some of these signals, some cells respond; to other signals, other cells respond. What a cell, a neuroblast, a growth cone actually does is dependent on the combina

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Growth cones respond to proximal and distal cues. The proximal cues in the extracellular matrix or other cells affect adhesion and result in chemotactic guidance. Distal cues are also in the extracellular matrix but they diffuse through it and result in the growth cone either moving towards the source (attractants) or away from it (repellants). These distal cues are chemotropic cues and can have different effects on different growth cones; what may be an attractant to one growth cone may be r

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Two important points emerge from this section. The first is the powerful effect of maternal contact on the development and later behaviour of their charges. In the Feldman study the disadvantages of prematurity were essentially overcome by early maternal contact. The second point is that some behavioural traits really do run in families, without being genetic. The Francis study clearly showed that some aspects of Open Field behaviour were the result of nursing care.

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Like vitamin E, vitamin K is fat-soluble and composed of a series of related compounds. Vitamin K is widely distributed in the diet (see Table 1) and it is absorbed from the small intestine with the assistance of bile acids. Vitamin K is also manufactured by the bacteria that inhabit the human large intestine and appears to be absorbed there too. The main role of vitamin K is in blood clotting. This process requires the presence of a number of different chemicals, called clotting factors, in

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Aspirin is able to release part of its ester group (Figure 15) in a hydrolysis reaction. Look again at the structure of aspirin, 2.8, and identify this group on the molecule. It is known as an acetyl group and accounts for aspirin also being called acetylsalicylic acid. The acetyl group on aspirin is fairly easily removed and can be available for forming another ester with an —﻿﻿OH group on another molecule; in this case, part of the structure that makes up the inside of the cavi

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Section 1 Superconductivity was discovered in 1911, and in the century since then there have been many developments in knowledge of the properties of superconductors and the materials that become superconducting, in the theoretical understanding of superconductivity, and in the applications of superconductors.

Section 2 A superconductor has zero resistance to flow of electric current, and can sustain a current indefinitely. The magnetic flux remains constant in a completel

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The second defining characteristic of a superconducting material is much less obvious than its zero electrical resistance. It was over 20 years after the discovery of superconductivity that Meissner and Ochsenfeld published a paper describing this second characteristic. They discovered that when a magnetic field is applied to a sample of tin, say, in the superconducting state, the applied field is excluded, so that B = 0 throughout its interior. This property of the superconducting s

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If you are interested in considering the role of the internet on science communication practices, you may find the following references are of interest: Wulf (1999), Rzepa (1999) and Rowland (1999a).

So far, you have been asked to reflect on your experiences of science communication both as a receiver and as a producer. You have also considered a definition for communication in terms of different types of media, noting how this influences the context for science communication (e.g. ‘f

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In 2000, the House of Lords Select Committee on Science and Technology produced an influential report that highlighted the complex and increasingly problematic relationship between contemporary science and society, particularly in the field of biotechnology (House of Lords Select Committee on Science and Technology, 2000). The report argued that many of these concerns were seen by the public to be the result of a perceived lack of transparency in the relationship between science, industry, pu

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